Liquid layers adhered to solid surfaces and that are in equilibrium with the vapor phase are common in printing, coating, and washing processes as well as in alveoli in lungs and in stomata in leaves. For such a liquid layer in equilibrium with the vapor it faces, it has been generally believed that, aside from liquid lumps, only a very thin layer of the liquid, i.e.
View Article and Find Full Text PDFHutchinson-Gilford progeria syndrome (HGPS) is a human progeroid disease caused by a point mutation on the LMNA gene. We reported previously that the accumulation of the nuclear envelope protein SUN1 contributes to HGPS nuclear aberrancies. However, the mechanism by which interactions between mutant lamin A (also known as progerin or LAΔ50) and SUN1 produce HGPS cellular phenotypes requires further elucidation.
View Article and Find Full Text PDFTransmission electron microscopy (TEM) is a unique and powerful tool for observation of nanoparticles. However, due to the uneven spatial distribution of particles conventionally dried on copper grids, TEM is rarely employed to evaluate the spatial distribution of nanoparticles in aqueous solutions. Here, we present a microchip nanopipet with a narrow chamber width for sorting nanoparticles from blood and preventing the aggregation of the particles during the drying process, enabling quantitative analysis of their aggregation/agglomeration states and the particle concentration in aqueous solutions.
View Article and Find Full Text PDFGold nanoparticles (AuNPs) confined in liposomes of diameters around 200 nm produce strong scattering signal owing to surface plasmon resonance, and therefore bright-field optical tracking of the AuNP-encapsulating liposomes can be conducted in living cells. Using an optical profiling technique called noninterferometric wide-field optical profilometry and a bright-field tracking algorithm, the polynomial-fit Gaussian weight method, we analyze three-dimensional (3D) motion of such liposomes in living fibroblasts. The positioning accuracy in three dimensions is nearly 20 nm.
View Article and Find Full Text PDFThis study investigated inflammatory effects of zinc oxide (ZnO) particles on vascular endothelial cells. The effects of 50 and 100-nm ZnO particles on human umbilical vein endothelial cells (HUVECs) were characterized by assaying cytotoxicity, cell proliferation, and glutathione levels. A marked drop in survival rate was observed when ZnO concentration was increased to 45 μg/ml.
View Article and Find Full Text PDFZwitterionic diazeniumdiolate, a nitric oxide precursor, was dissolved in basic buffer solution (pH=9.0) and encapsulated in thermo-sensitive liposomes composed of phospholipids of different sensitive temperatures. The basic intra-liposomal environment dramatically delayed spontaneous NO release.
View Article and Find Full Text PDFIron oxide nanoparticles can serve as a heating source upon alternative magnetic field (AMF) exposure. Iron oxide nanoparticles can be mixed with thermosensitive nanovehicles for hyperthermia-induced drug release, yet such a design and mechanism may not be suitable for controllable drug release applications in which the tissues are susceptible to environmental temperature change such as brain tissue. In the present study, iron oxide nanoparticles were entrapped inside of thermosensitive liposomes for AMF-induced drug release while the environmental temperature was maintained at a constant level.
View Article and Find Full Text PDFSuperparamagnetic iron oxide (SPIO) nanoparticles are very useful in cell imaging; meanwhile, however, biosafety concerns associated with their use, especially on therapeutic stem cells, have arisen. Most studies of biosafety issues focus on whether the nanoparticles have deleterious effects. Here, we report that Ferucarbotran, an ionic SPIO, is not toxic to human mesenchymal stem cells (hMSCs) under the conditions of these experiments but instead increases cell growth.
View Article and Find Full Text PDFXanthine oxidase (XOD) consists of two identical subunits. For the past 50 years or so, it was assumed that the two subunits carry out catalysis independently. Herein, we report that the presence of 6-formylpterin (6FP) or other substrates (such as xanthine or xanthopterin) at one of the two active sites affects the binding affinity and catalysis rate of 6FP at the other.
View Article and Find Full Text PDFActivated microglia in acute and chronic neurodegenerative disease of the central nervous system (CNS) can produce large amounts of free radicals, such as reactive oxygen species (ROS), which subsequently contribute to neuropathogenesis. Thus, it is believed that the induction of microglial deactivation can reduce neuronal injury. Buckminsterfullerene (C60) derivatives that possess free radical scavenging properties have been demonstrated to prevent neuronal cell death caused by excitotoxic insult.
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